<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>运算符</title>
</head>
<body>

</body>
<script>
    let num = "10";
    document.write(num + 5 + "<br>")            // 105
    document.write(num + "5" + "<br>")          // 105
    document.write(num - 5 + "<br>")            // 5
    document.write(num * 5 + "<br>")            // 50

    let num1 = 10;
    document.write(num == num1);                // ==只比较值是否相同
    document.write(num === num1);               // ===比较数据类型和值是否相同
</script>
</html>